I have straightened it out since! Ballsed it up right at the end and it got crinkled so had to readjust. It's a little faffy, but if you're not a dipshit like me, you should be fine.I bought a framing kit off Amazon for my signed shirt for like £40. It's a bit of a faff but worth it.
This is the one I used, turns out it's £50 but still much cheaper than getting it done professionally: https://amzn.eu/d/70pYI2E